Brown Recluse Spider Bite

What is Brown Recluse Spider Bite?

The Brown Recluse Spider is a species of spiders found in the Southern and Central region in the United States. They are suited to warm climates and are poisonous. They are timid creatures that do not bite unless an individual traps them against his/her skin. However, a The bite of the spider can also prove to be life-threatening in some cases. They infest areas that are dark and sheltered such as piles of wood, rocks, leaves and even in people’s houses.

The Brown Recluse Spider – Source

How to identify a Brown Recluse Spider?

It is among the few species of spiders whose bite is venomous and life-threatening. It is important to identify the differences between this Spider and other species of spiders by its characteristic features. It has a violin-shaped dark patch at the back of its head, but this patch is not easily noticeable. The spiders are yellowish tan or dark brown and have darker legs. The legs stretch about 1 inch in length and they have six eyes instead of eight.

How does the Venom affect the body?

The venom of the Brown Recluse Spider is extremely poisonous, and it is toxic to the tissues and cells of the body. The venom is made of some enzymes where one of them damages the local cell membranes. It leads to a breakdown of skin, blood vessels and fat. As a result tissues also die.

The individual’s body releases anti-inflammatory agents in response to the injection of venom on the body. The immune system produces white blood cells to fight diseases. However, sometimes these inflammatory agents can cause injury. The venom may have significant side effects such as:

  1. Loss of blood clotting ability
  2. Kidney damage
  3. Damage to red blood cells
  4. Low platelet count
  5. Coma
  6. Death


The Brown Recluse Spiders only come out during the night to prey on insects. They are not aggressive and they only bite when they are trapped in the skin.


  • Bite may sting
  • Pain, burning & itching in the area of the bite
  • Formation of a small white blister at the site of injury
  • Nausea
  • Rash
  • Fever
  • Chills
  • Sweating
  • General discomfort
  • Discoloration occurs about 12 – 36 hours after the bite
  • Site may become deep blue or purple with a whitish ring and a large red area
  • Dark ulcers or blisters may appear and continue to grow for weeks near the bite
  • Muscle pain
  • Convulsions


    • Examination of the patient’s wound
    • Enzyme-linked immune sorbent assay to identify the venom of the brown recluse spider
    • Examination of red blood cells & White Blood Cells
    • Platelet count
    • Testing of bilirubin
    • Testing of liver enzymes
    • Urinalysis


    • Red Blood Cells: The venom of the brown recluse spider contains sphingomyelinase D which reacts and results in conditions of hemolysis leading to hemolytic anemia. Intravascular and extravascular hemolysis is other possible conditions that may emerge. Usually, hemoglobin is not plasma-free, but in case of intravascular hemolysis, plasma free hemoglobin is observed. If direct antiglobulin tests have a positive result, it means, that antibodies are present on the surface of the red blood cells.
    • White Blood Cells: The spider bite results in mild leukocytosis and sometimes leucopenia. High levels of erythrocyte sedation rate suggest possible inflammation may happen as a response to the bite. The layer of fat under the skin also undergoes inflammation due to the presence of thrombosis, neutrophils and eosinophils.
    • Urinalysis: Hemolysis may cause an increase in the levels of bilirubin. Liver enzymes such aspartate aminotransferase and alanine transaminase are also observed at higher levels. Hemolysis also causes high lactate dehydrogenase and hemoglobinuria. High urobilinogen gives urine a darker color and is suggestive of extravascular hemolysis.
    • Platelet: Sphingomyelinase D causes thrombocytopenia which affects the platelets. Presence of degenerative fibrin products in high quantities suggests a condition of disseminated intravascular coagulation. This may lead to renal failure, multiple organ failures or even death.


  • Keep areas such as the yard and basement clean to avoid stacking up wood and other items providing favorable warm and dark condition for the infestation
  • Dust shoes & check the insides before wearing them
  • Dust clothes & bed sheets before using them to avoid trapping the spiders
  • Use sealed plastic bags to store tools to avoid encountering spiders
  • While moving cardboard, rocks or wood from one place to another, individuals must use gloves as they are favorable areas for the spiders to stay
  • Do not leave personal belonging such as towels & clothes on the floor

First aid in case of a bite

  • Clean the wound by washing it with soap and water
  • Keep the wound higher than the rest of the body to slow the spread of the venom
  • To limit the pain and swelling of the wound, apply an ice pack or cool compress by alternating between 10 minutes on the wound and 10 minutes off it


  • Keeping the wound elevated: As mentioned above, this should be one of the primary steps adopted to treat a spider bite. Placing the wound higher will hinder the spreading of venom to other parts of the body. In this case, the effects are restricted to the area that is immediate to the wound. It also helps in quicker recovery.
  • Rest: The venom contains many enzymes that have adverse effects on the health of an individual. It affects blood count, platelets and other major components of the body. The body requires ample rest to be able to cope with these effects and recover completely.
  • Medication: Antibiotic ointments, dapsone, and oral steroids are prescribed to individuals who suffer from a brown recluse spider bite. Aspirin and antibiotic medications can also be taken to improve the condition of platelets. To quicken the process of wound healing antihistamines can be taken as well.

When to Visit a Doctor?

Spider bites are usually trivial and do not need special attention. However, in case of a brown recluse spider bite, a doctor must be immediately consulted to avoid any further complications. The bite can lead to severe and life-threatening consequences.

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